These boxes are ours.(氦为单数形式)

These boxes are ours氦为单数形式 These boxes are ours.(氦为单数形式) Whose teachers are these They are ours改成单数形式 These are boxes. (改为单数句） These boxes are brown.变单数 these shoes are ours.单数句 句型转换 Are these your pencil-boxes?(改为单数形式） ___ ___ your___? These are ours改为单复数形式 these are new books.改为单数形式 these are chinese books 改为单数形式 These are Chiese buses.变为单数形式 are these apples?改为单数形式